"Bridget Jones's Diary" hunk and one of PEOPLE's 50 Most Beautiful People of 2001, Colin Firth, 41, who normally shies away from celebrity parties, couldn't resist the invitation to join his current "American Girl" costar Kelly Preston and Britain's Queen Elizabeth at a gala polo match on Sunday, reports PEOPLE. ("American Girl" is loosely based on the 1958 romantic comedy "The Reluctant Debutante," with Rex Harrison and Kay Kendall.) Basking in the uncharacteristic 80-degree heat, Firth, 41, joked at England's Guards Polo Club that last year's PEOPLE honor was "the crowning glory of my career. Whenever I am interviewed I am asked about it." Well, at least by PEOPLE he is. The prestigious Cartier International Polo Day was the sport's way of saying "thank you" to Her Majesty for her 50 years on the throne and was the last great event of the British summer social season. But it was all new to Firth. "I don't normally do events like this but I am working with Kelly Preston, and she got invited and called me up and gave me a budge, saying it would be a lot of fun." And can Firth explain polo? "I have never seen it before," says Firth, who was enjoying the hospitality with his son Will, 11. "It seems like lots of men on horses riding around dangerously."